Method for the manufacture of metal components requiring chip removing machining

ABSTRACT

Identical ring-shaped metal blanks are machined whereby each blank forms a plurality of identical components. The blanks are first machined on both sides, and then a stack of the blanks is clamped axially adjacent one another on an arbor. Tools machine the blanks for reshaping the blanks. One of the tools is a slitter which makes axial cuts through the stack to separate each blank into a plurality of components distributed around the axis.

BACKGROUND OF THE INVENTION

The invention pertains to methods and apparatus for the manufacture ofmetal components requiring chip removal machining.

Tools for chip removing machining, such as milling tools, drillingtools, turning tools and the like commonly include miscellaneouscomponents which are of a limited size in relation to the tool in itsentirety and which must be machined to high accuracy. Examples of suchcomponents are cassettes and wedges for milling tools, shims fordrilling and turning tools, clamps and chip breakers for milling tools,etc. Critical surfaces on such components often require toleranceswithin the range of 0.005-0.02 mm. The same fine tolerances are alsorequired for holes in the components and for serrations, thereon. Suchcomponents are usually made of steel, which requires hardening.

Manufacturing methods, known hitherto, require individual handling ofmetal blanks, which are slightly larger than the components will beafter all machining has been completed. Usually, the blanks are cast insteel, and then the individual blanks are machined in a series ofdifferent operations. In the case of, for instance, cassettes formilling tools, seats are milled for cutting inserts at a certainmachining station, while grinding of external surfaces takes place atanother station. At additional stations, serrations may be produced bythe milling of an external surface, and holes may be drilled andpossibly screw-threaded.

Between these stations, the individual blanks have to be handledseparately since they have to be released from the fixture in questionafter a first machining operation and then re-mounted in another fixturefor the next machining operation. In case one and the same blank is tobe submitted to many machining operations, the handling as a whole willbe time-consuming and expensive. Furthermore, the individual handling atand between different machining stations has the aggravatingdisadvantage that the dimensional accuracy may suffer. Thus, if allblanks are not positioned and fixed in the same way, there is a riskthat individual components get unacceptable tolerance deviations. Itshould also be mentioned that the requisite hardening of theblanks/components has to be carried out individually.

Objects and Features of the Invention

The present invention aims at obviating the above-mentioneddisadvantages of the previously applied manufacturing method and, in afirst aspect, at providing an improved method for the manufacture ofcomponents which require chip removing machining. A primary object ofthe invention is to provide a manufacturing method which permits anaccurate machining of the requisite metal blanks without the need tomove, between different machining stations and fixtures, respectively, aplurality of components which in all essentials could instead bemachined to completion at one machining station. An object is also toprovide a manufacturing method, which permits an efficient and therebyinexpensive production.

According to the invention, at least the primary object is obtained by amethod of manufacturing metal components, comprising the step of:

A) face-machining opposite sides of each of a plurality of ring-shapedmetal blanks;

B) securing the face-machined blanks in axially adjacent relationshipalong an axis, whereby the blanks are immovable relative to one another;and

C) performing a plurality of different chip-removing machiningoperations on each blank for reshaping the blanks, one of the machiningoperations comprising making axial cuts through the blanks in adirection parallel to the axis to separate each blank into a number ofcomponents distributed around the axis.

Another aspect of the invention involves an apparatus for machiningmetal components. The apparatus includes an arbor which defines an axis.The arbor has a stop surface at one axial end thereof and a clamp at anopposite axial end thereof. A set of ring-shaped metal blanks is clampedon the arbor between the stop surface and the clamp so as to beimmovable relative to one another. A plurality of machining tools isprovided for performing a plurality of different chip-removing machiningoperations on each blank for reshaping the blanks. One of the machiningtools is arranged for making axial cuts through the blanks in adirection parallel to the axis for separating each blank into a numberof components distributed around the axis.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic, exploded view showing a number of tangentiallyspaced, finish-machined components, as well as a number of componentsarranged axially one after the other,

FIG. 1A is a side elevational view of an arbor according to the presentinvention;

FIG. 2 is a partial cross-sectional side view showing a number of ringblanks fixed on the arbor,

FIG. 3 is a side view of a single ring blank,

FIG. 4 is a cross-section through the ring blank according to FIG. 3,

FIG. 5 is an enlarged cross-section through the arbor according to FIG.2 with a number of components positioned peripherally on the arbor, and

FIG. 6 is an enlarged, partial cross-section through an arbor and anumber of other components illustrating other feasible machiningoperations than those shown in FIG. 5.

DETAILED DESCRIPTION OF A PREFERRED Embodiment of the Invention

In FIG. 1 a number of metal components 1 are shown, of which some aretangentially spaced and located in a ring-shaped configuration, whileothers are arranged side by side in an axial extension of one of thecomponents in the ring formation. In the shown example, these componentsconsist of wedges having the purpose of clamping a cutting insert in acassette included in a milling tool (wherein the wedges would bearranged in the shown ring shape). In addition to a number of planarsurfaces, this type of wedge is delimited by a concavely arched surface2.

Reference is now made to FIGS. 1A-6, which illustrate schematically amethod according to the invention for making the wedges, together with adevice for carrying out the method.

In FIGS. 3 and 4 a metal blank 3 in the shape of a ring is shown (in asmall scale). In this case, the ring is cylinder-shaped in that the sameis delimited by a cylindrical inner surface 4 and a likewise cylindricalouter surface 5, the two opposite side surfaces 6 being planar andmutually substantially parallel. Alternatively, the ring and arbor couldbe non-cylindrically shaped, e.g., polygonally shaped in cross-section.

In FIGS. 1A, 2, 5 and 6, reference numeral 7 designates an arbor whichat one end has a stop member 8 and at the opposite end an axiallymovable clamping mechanism generally designated 9. In the preferredembodiment, this clamping mechanism includes a cage 10 axially movablealong the arbor, as well as a nut 11, which is fastened with screws on athreaded end portion 12 of the arbor. In the example, the stop member 8consists of a thickened portion of the arbor. This thickened portion aswell as the cage 10 have planar shoulder surfaces 13 and 14,respectively, which extend perpendicularly to the geometrical,longitudinal axis of the arbor.

Two cutting tools, shown schematically, are in the form of so-calledslitting cutters 15. Slits or cuts may be milled in the ring blanks 3 bymeans of these cutters, which blanks are mounted in axially adjacentrelationship on the arbor and fixed thereon by means of the clampingmechanism. A number of circumferentially spaced grooves 16 extendingaxially along the arbor are provided in order to be able to receiveperipheral edges of the cutters whilst they cut completely through theset of rings. Partially circular recesses 17 serving as extensions ofthe grooves 16 are formed in the portion 8, which serves as a stopmember. Analogous recesses 17′ are formed in the cage 10.

An important feature of the method according to the invention consistsof using, as manufacturing blanks, ring blanks 3 which individually havea volume large enough to form a plurality of finished components 1. Inthe example according to FIG. 1, each individual ring blank 3 is assumedto be large enough to permit the manufacture of ten components.

In a first manufacturing step, the individual ring blank isface-machined on the two opposite sides 6 thereof. This machining,which, in practice, can consist of face milling or face grinding, can becarried out in a conventional way, to an accuracy within the range of0.005-0.02 mm. In a second step, two or more face machined ring blanksare put together one after the other along a common geometrical axis,and fixed in relation to each other while forming a stable set of rings.In the example according to FIG. 2, twelve ring blanks are shown in sucha set. In practice, the rings are axially inserted onto the arbor 7, andthen the cage 10 is applied and tightened by means of the nut 11. Thanksto the fact that all the ring blanks have face-machined, parallel sidesurfaces 6, and that the pressing surfaces 13, 14 extend perpendicularlyto the longitudinal axis of the arbor, an immovable clamping of therings in the set is achieved.

When the set of ring blanks have been fixed, the ring set is submittedto a number of chip removing machining operations, the nature of whichdepends on the type of component which is desired. In FIGS. 5 and 6examples are given as to how drills 23, 23′, 23″ may provide a possiblemeans of drilling holes of different types in the ring blanks, e.g. athrough-hole 18 for receiving a fastener screw, a hole 18′ which forms aspring seat, and a hole 18″, respectively, for a pin. Furthermore,serrations 19 may be formed by means of a milling cutter along one sideof the component. In other respects, a number of face machined surfaces20 are formed by means of one or more facemills which with modem millingequipment may be given a very close dimensional accuracy. Although thedrilling operations are carried out one-by-one in different positions,all milling operations may be carried out by relative axial movementsbetween the ring set and the milling tool, whereby each surface orserration can be machined in one single pass. In other words, the tooland/or the ring set is/are transported in one single, unbroken motionfrom one end of the ring set to the opposite one.

In a number of concluding machining operations, the ring set is giventangentially spaced and radially oriented through-cuts, which formindividual components 1 from each blank 3. This may be carried out withthe above-mentioned slitting cutters 15, which may cut through the ringsentirely, in that the peripheral portions of the cutters carrying thecutting inserts may be led down into the grooves 16 and the recesses 17,17′, respectively, in the stop member 8 and the cage 10, respectively.This slit cutting can be carried out by axial displacement of themilling-cutter through the ring set while forming thecomponent-separating slits 21, whereby the individual components, whichare separated from each other, still hang together because they areclamped between the cage 10 and the stop member 8. In other words, thefinish-machined components will be separated from the arbor 7 only whenthe nut 11 and the cage 10 have been separated.

In cases where the components are intended to be included in tools forchip removing machining, they are usually manufactured in steel. Theinvention offers a possibility to carry out the requisite hardening ofthe steel before the above-mentioned machining operations are started.In other words, the unmachined ring blanks 3 while in the unmachinedstate may be submitted to hardening. In that manner, the followingadvantages are won, the machining accuracy is improved, and thecomparatively large ring blanks facilitate and hasten the requisitehandling in connection with hardening (the numerous, small componentswhich are extracted from each ring blank would require a handling whichis more time-consuming).

A significant advantage of the invention is that numerous components maybe machined and extracted at the same time without having to berepeatedly moved between different machining stations and fixtures.This, in turn, ensures high accuracy of the components after allmachining has been completed. In all essentials, all components becomeidentical.

In the embodiments exemplified, the ring blanks 3 are cylinder-shapedand used for the manufacture of wedges which have concavely archedsurfaces 2 of the type shown in FIG. 1. Other components may, however,require differently shaped surfaces, e.g. planar surfaces. In case thering blank is cylindrical, a final face machining is required when thecomponents have been separated from each other.

Although after-treatment of the individual components may be needed, themajority of machining operations may be carried out while the ringblanks are kept together in a set which has a stable shape. In thisconnection, it has been pointed out that the ring blanks, as well as thearbor, may be of a shape other than cylindrical. The ring blanks, forinstance, as well as the arbor, may be of a polygonal shape incross-section (e.g. quadrangular, pentagonal and hexagonal,respectively). In such cases, the arbor and the ring blanks,respectively, may be formed and located in such a way in relation toeach other that gaps result between the interior of the ring and theoutside of the arbor, with the peripheral portion of the slitting cutterbeing housed in these spaces. In other words, there would be no need forproviding grooves in the arbor.

Other Feasible Modifications of the Invention

The invention is not limited to the embodiments illustratedschematically in the drawings. Thus, it is feasible to dispose the ringblanks in a set in which ring-shaped shims between adjacent ring blanksare included. In other words, the ring blanks do not need to be pressedin direct surface contact with each other as is shown in FIG. 2.

Although the ring blanks, in the preferred embodiments, are placedconcentrically in relation to a mutual geometrical axis, e.g. on anarbor common for all ring blanks it is also feasible to mount the ringblanks without any requirement regarding concentricity. Although theabove invention has been described in connection with componentsintended to be included in different types of tools for chip removingmachining, the same may also apply for other arbitrary, small componentsirrespective of the material thereof.

What is claimed is:
 1. A method of manufacturing metal components,comprising the steps of: A) face-machining opposite sides of each of aplurality of ring-shaped metal blanks; B) securing the face-machinedblanks on an arbor in axially adjacent relationship along an axisdefined by the arbor, whereby the blanks are immovable relative to oneanother; and C) performing a plurality of different chip-removingmachining operations on each blank for reshaping the blanks while theblanks remain secured on the arbor, one of the machining operationscomprising employing a cutter for making axial cuts through the blanksin a direction parallel to the axis to separate each blank into a numberof components distributed around the axis, wherein during a cuttingoperation an edge of the cutter is received in an axial groove formedbetween an outer periphery of the arbor and inner peripheries of all ofthe blanks.
 2. The method according to claim 1 wherein step B furtherincludes pressing the side surfaces of adjacent blanks into directcontact with one another.
 3. The method according to claim 1 wherein theblanks that are face-machined in step A comprise hardened steel blanks.4. The method according to claim 1 wherein the one machining operationwhich makes axial cuts comprises a slit cutting operation.
 5. The methodaccording to claim 1 wherein the one machining operation which makesaxial cuts makes each of such axial cuts through all of the blanks fromone end-most blank to another end-most blank.
 6. The method according toclaim 1 wherein step A comprises face-machining opposite sides of eachof a plurality of ring-shaped metal blanks of circular cross-section. 7.The method according to claim 1 wherein step A comprises face-machiningopposite sides of each of a plurality of ring-shaped metal blanks ofnon-circular cross-section.
 8. The method according to claim 1 whereinthe blanks used in step A are identical, and the components formed instep C are identical.
 9. The method according to claim 1 wherein anotherof the machining operations performed in step C comprises drilling ahole in each blank.
 10. The method according to claim 1 wherein duringstep C the edge of the cutter is received in the groove which isdisposed in the outer periphery of the arbor.